Missing Malaysia Airlines jet

FILE - In this Sunday, March 9, 2014, file photo, a man looks out from a viewing gallery as a Malaysia Airlines aircraft sits on the tarmac at Kuala Lumpur International Airport in Sepang, Malaysia. With the search for the missing Malaysia Airlines Flight 370 entering its eighth day, scenarios involving piracy or hijacking are increasingly being talked about as possible explanations for the disappearance of the Boeing 777 with 239 people on board. (AP Photo/Lai Seng Sin, File)

In this Thursday March 13, 2014 photo, university students hold a candlelight vigil for passengers on the missing Malaysia Airlines Flight MH370 in Yangzhou, in eastern China's Jiangsu province. China on Friday urged Malaysia's government to release any information it has regarding the missing Malaysia Airlines jetliner to help narrow the search area.

Graphic: How a search for a missing aircraft is conducted

FILE – In this Nov. 14, 2005 file photo, clouds hang over the North Sentinel Island, in India's southeastern Andaman and Nicobar Islands. India used heat sensors on flights over hundreds of uninhabited Andaman Sea islands Friday, March 14, 2014, and will expand its search for the missing Malaysia Airlines jet farther west into the Bay of Bengal, officials said. The Indian-controlled archipelago that stretches south of Myanmar contains 572 islands covering an area of 720-by-52 kilometers. Only 37 are inhabited, with the rest covered in dense forests. (AP Photo/Gautam Singh, File)

Graphic: The search for the missing Malaysia Airlines plane

Indonesian Air Force personnel of the 5th Air Squadron "Black Mermaids" listen to a briefing as an operation map is projected on the wall following a search mission for the missing Malaysia Airlines Boeing 777 that was conducted over the Strait of Malacca, at Suwondo air base in Medan, North Sumatra, Indonesia, Friday, March 14, 2014. The jetliner vanished nearly a week ago with 239 people aboard. (AP Photo/Binsar Bakkara)

Graphic: How an airplane transponder works

FILE - In this May 30, 2013 file photo, visitors and staff at the U.S. Geological Survey's Earth Resources Observation and Science Center, EROS, gather near a scale model of the Landsat 7 satellite. The facility is helping in the international search for a missing Malaysian jetliner. EROS collects, archives and makes available for download more than 400 data-filled images of the Earth each day. The images coming from EROS have not produced any solid leads in the case of the missing plane, but the center's Disaster Response Coordinator Brenda Jones said she hopes the center's work eventually will help lead to answers. (AP Photo/Dirk Lammers, File)

A relative of Chinese passengers aboard the missing Malaysia Airlines flight MH370 grieves alone in a corridor at a hotel in Beijing Friday, March 14, 2014. A U.S. official said that the missing Malaysia Airlines plane pinged a satellite for four hours after it went missing, indicating that it may have stayed in the air long after its last contact with the ground. Malaysian authorities are widening their search westward, toward India, as a result. (AP Photo/Ng Han Guan)

A Muslim boy leaves a mosque after Friday prayers, just down the road from the home of Fariq Abdul Hamid, co-pilot of the missing Malaysia Airlines jetliner MH370, center, Friday, March 14, 2014 in Shah Alam, Malaysia. The pilots of the missing Malaysia Airlines passenger jet were a contented middle-aged family man passionate enough about flying to build his own simulator and a 27-year-old contemplating marriage who had just graduated to the cockpit of the Boeing 777. Details about the men have emerged from interviews with neighbors, Malaysia Airlines staff, a religious leader and from social networks and news reports in Malaysia and Australia.(AP Photo/Eileen Ng)

Malaysia's Minister of Transport Hishamuddin Hussein, center, takes his leave after a press conference regarding missing Malaysia Airlines jetliner MH370, Friday, March 14, 2014 in Sepang, Malaysia. The international search for the missing Malaysian jetliner expanded westward Friday toward the Indian Ocean amid signs the aircraft may have flown on for hours after its last contact with air-traffic control nearly a week ago.(AP Photo/Wong Maye-E)

Lt. Col Bambang Sudewo, commander of the 5th Air Squadron "Black Mermaids" examines a map following a search operation for the missing Malaysia Airlines Boeing 777 that was conducted over the Strait of Malacca, at Suwondo air base in Medan, North Sumatra, Indonesia, Friday, March 14, 2014. The jetliner vanished nearly a week ago with 239 people aboard. (AP Photo/Binsar Bakkara)

A marshall directs an Indonesian Air Force Boeing 737 "Surveiller" of the 5th Air Squadron "Black Mermaids" to park on the tarmac following a search operation for the missing Malaysia Airlines Boeing 777 that was conducted over the Strait of Malacca, at Suwondo air base in Medan, North Sumatra, Indonesia, Friday, March 14, 2014. The jetliner vanished nearly a week ago with 239 people aboard. (AP Photo/Binsar Bakkara)

A cabin crew of the Vietnam Air Force is seen onboard a flying AN-26 Soviet made aircraft during a search operation for the missing Malaysia Airlines flight MH370 plane over the southern sea between Vietnam and Malaysia Friday, March 14, 2014. Vietnam says it has downgraded but not stopped its search for the missing jetliner in the South China Sea and has been asked by Malaysian authorities to consider sending planes and ships to the Strait of Malacca. (AP Photo/Na Son Nguyen)

Officer Lang Van Ngan of the Vietnam Air Force looks out the window onboard a flying AN-26 Soviet made aircraft during a search operation for the missing Malaysia Airlines flight MH370 plane over the southern sea between Vietnam and Malaysia Friday, March 14, 2014. Vietnam says it has downgraded but not stopped its search for the missing jetliner in the South China Sea and has been asked by Malaysian authorities to consider sending planes and ships to the Strait of Malacca. (AP Photo/Na Son Nguyen).

A message card reading "MH370 comes back safely" is tied up for passengers aboard a missing Malaysia Airlines plane, outside a shopping mall in Kuala Lumpur, Malaysia, Friday, March 14, 2014. A U.S. official said that the missing Malaysia Airlines flight MH370 pinged a satellite for four hours after it went missing, indicating that it may have stayed in the air long after its last contact with the ground. Malaysian authorities are widening their search westward, toward India, as a result. (AP Photo/Lai Seng Sin)

Cabin crews of Vietnam Air Force are seen onboard a flying AN-26 Soviet made aircraft during a search operation for the missing Malaysia Airlines flight MH370 plane over the southern sea between Vietnam and Malaysia Friday, March 14, 2014. Vietnam says it has downgraded but not stopped its search for the missing jetliner in the South China Sea and has been asked by Malaysian authorities to consider sending planes and ships to the Strait of Malacca. (AP Photo/Na Son Nguyen)

Malaysian Prime Minister Najib Razak, second from left, offers a prayer at a mosque in Sepang, Malaysia, Friday, March 14, 2014. A U.S. official said that the missing Malaysia Airlines plane pinged a satellite for four hours after it went missing, indicating that it may have stayed in the air long after its last contact with the ground. Malaysian authorities are widening their search westward, toward India, as a result. (AP Photo/Lai Seng Sin)

A P3C patrol plane of the Japan Maritime Self-Defense Force sits on the taxi way at Sepang air force base, Malaysia, Friday, March 14, 2014. Nearly every navy with a presence in Southeast Asia is involved in the extensive search for the Malaysia Airlines Boeing 777 that disappeared early Saturday. Japan, which has been increasing its effort to participate in regional humanitarian missions, deployed two P-3C aircraft to the area earlier in the day. (AP Photo/Kyodo News)

Relatives of Chinese passengers aboard missing Malaysia Airlines flight MH370 leave from a room at a hotel in Beijing, China, Friday, March 14, 2014. A Malaysia Airlines plane sent signals to a satellite for four hours after the aircraft went missing, an indication that it was still flying for hundreds of miles or more, a U.S. official briefed on the search said Thursday. (AP Photo/Ng Han Guan)

This photo provided by the U.S. Navy shows the Royal Malaysian Navy corvette KD Terengganu and a U.S. Navy MH-60R Sea Hawk helicopter conduct a coordinated air and sea search for a missing Malaysian Airlines jet in the Gulf of Thailand. (AP Photo/U.S. Navy, Operations Specialist 1st Class Claudia Franco)

A man walks out of a room reserved for relatives of Chinese passengers aboard missing Malaysia Airlines flight MH370 at a hotel in Beijing, China, Saturday, March 15, 2014. Investigators have concluded that one or more people with significant flying experience hijacked the missing Malaysia Airlines jet, switched off communication devices and steered it off-course, a Malaysian government official involved in the investigation said Saturday. (AP Photo/Ng Han Guan)